Segment Information - Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019
Segment Reporting Information [Line Items]
Gross revenues	$ 339,357	$ 319,587
Revenues	338,097	318,511
Gross profit	32,465	23,421
Operating income	8,774	2,220
Segment assets	672,754		$ 633,394
Electrical Infrastructure [Member]
Segment Reporting Information [Line Items]
Gross revenues	31,532	44,701
Revenues	31,532	44,701
Gross profit	104	3,383
Operating income	(1,844)	657
Segment assets	137,643		155,880
Oil Gas & Chemical [Member]
Segment Reporting Information [Line Items]
Gross revenues	57,786	75,562
Revenues	57,530	75,491
Gross profit	3,635	5,625
Operating income	(1,773)	514
Segment assets	93,866		91,959
Storage Solutions [Member]
Segment Reporting Information [Line Items]
Gross revenues	150,752	113,767
Revenues	150,067	112,762
Gross profit	21,055	9,553
Operating income	9,452	285
Segment assets	206,144		188,912
Industrial [Member]
Segment Reporting Information [Line Items]
Gross revenues	99,287	85,557
Revenues	98,968	85,557
Gross profit	7,671	4,860
Operating income	2,939	764
Segment assets	68,091		90,336
Other Segments [Member]
Segment Reporting Information [Line Items]
Segment assets	167,010		$ 106,307
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Gross revenues	1,260	1,076
Intersegment Eliminations [Member] \| Oil Gas & Chemical [Member]
Segment Reporting Information [Line Items]
Gross revenues	256	71
Intersegment Eliminations [Member] \| Storage Solutions [Member]
Segment Reporting Information [Line Items]
Gross revenues	685	1,005
Intersegment Eliminations [Member] \| Industrial [Member]
Segment Reporting Information [Line Items]
Gross revenues	$ 319	$ 0

Gross revenues before intersegment eliminations

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